1. Field
Exemplary embodiments of the present disclosure relate to an image forming apparatus, such as a copier, a printer, a facsimile machine, and a multifunctional device having at least two of the foregoing capabilities, and more specifically, to an image forming apparatus including a removable fixing device.
2. Description of the Background Art
Related-art image forming apparatuses, such as copiers, facsimile machines, printers, or multifunction apparatuses having at least one of copying, printing, scanning, and facsimile functions, typically form an image on a recording medium according to image data. In such an image forming apparatus, for example, a charger uniformly charges a surface of an image carrier; an optical writer emits a light beam onto the charged surface of the image carrier to form an electrostatic latent image on the image carrier according to the image data; a development device supplies toner to the electrostatic latent image formed on the image carrier to make the electrostatic latent image visible as a toner image; the toner image is directly transferred from the image carrier onto a recording medium or is indirectly transferred from the image carrier onto a recording medium via an intermediate transfer member; a cleaner then cleans the surface of the image carrier after the toner image is transferred from the image carrier onto the recording medium; finally, a fixing device applies heat and pressure to the recording medium bearing the toner image to fix the toner image on the recording medium, thus forming the image on the recording medium.
Such a fixing device employed in an image forming apparatus may include a non-contact-type temperature detector to detect the surface temperature of a fixing member (e.g., heating roller).
For example, for an image forming apparatus like that described in JP-2002-139952-A, a thermopile serving as the temperature detector is disposed opposing a heating roller serving as the fixing member without contacting the heating roller. In accordance with a temperature detected by the thermopile, the output of the heater within the heating roller is controlled to adjust the surface temperature (fixing temperature) of the heating roller. The thermopile is disposed outside the fixing device in the image forming apparatus to minimize temperature increase of the thermopile itself. Thus, the thermopile is disposed opposing the heating roller outside the fixing device to control the temperature of the heating roller.
For the above-described conventional art, a non-contact-type temperature detector is used to detect the surface temperature of the fixing member. Such a configuration has an advantage over a contact-type temperature detector (e.g., contact-type thermistor) for detecting the surface temperature of the fixing member in contact with the surface of the fixing member, in that the fixing member and the temperature detector are not worn by sliding contact of the fixing member with the temperature detector. In addition, the costly, non-contact-type temperature detector is disposed outside the fixing device in the image forming apparatus. Such a configuration is advantageous in that it is possible to reduce the production cost of the fixing device which is replaced more often than the entire image forming apparatus. However, by locating the non-contact-type temperature detector outside the fixing device, the temperature detector may be affected by air flow in the image forming apparatus. As a result, the ambient temperature around the temperature detector may be disturbed, thus preventing precise detection of the surface temperature of the fixing member. In such a case, the fixing temperature of the fixing member may fluctuate, resulting in fixing failure of a resultant image.